Management of Sigmoid Polyps Found on Colonoscopy
The management of sigmoid polyps depends critically on their histology, size, and number: all adenomatous polyps should be completely removed during colonoscopy, with surveillance intervals determined by the highest-risk features present. 1
Immediate Management During Colonoscopy
All identified polyps should be completely removed and sent for histological examination to determine whether they are adenomatous (neoplastic) or hyperplastic (non-neoplastic). 2
Polyps ≥10 mm should be removed using hot snare polypectomy for pedunculated lesions, with prophylactic mechanical ligation considered for those with head ≥20 mm or stalk thickness ≥5 mm to reduce bleeding risk. 1
Document the size (in millimeters), number, exact location, and whether complete removal was achieved, as this information is essential for determining surveillance intervals. 2
Risk Stratification Based on Pathology Results
Low-Risk Findings
For 1-2 small tubular adenomas (<10 mm) with low-grade dysplasia: next surveillance colonoscopy in 7-10 years. 1
For small hyperplastic polyps in the rectosigmoid region: rescreen as average-risk patients with colonoscopy in 10 years, as these carry no increased colorectal cancer risk. 3
Intermediate-Risk Findings
For 3-4 tubular adenomas <10 mm: surveillance colonoscopy in 3-5 years. 1, 4
The precise timing within this 3-5 year window should be based on quality of baseline examination, family history, and patient preferences. 1
High-Risk Findings (Any of the Following)
- Adenoma ≥10 mm in size
- Tubulovillous or villous histology
- High-grade dysplasia
- ≥5 adenomas of any size
For any high-risk feature: surveillance colonoscopy in exactly 3 years. 2, 1, 4
Special Considerations and Pitfalls
Incomplete Removal
If any polyps were removed piecemeal, a 6-month follow-up colonoscopy is required to verify complete removal before establishing the standard surveillance schedule. 1
For malignant polyps with invasion into the submucosa, assess margin status, depth of invasion, lymphovascular invasion, and tumor differentiation to determine if surgical resection is needed. 2
Multiple Polyps (>10 adenomas)
- Surveillance colonoscopy in 1 year and consider genetic testing for polyposis syndromes such as familial adenomatous polyposis or Lynch syndrome. 1
Proximal Hyperplastic Polyps
Large (≥1 cm), sessile, proximally located hyperplastic polyps warrant surveillance similar to adenomas, as they can progress through the serrated pathway. 3
Hyperplastic polyposis syndrome (≥5 hyperplastic polyps proximal to sigmoid with 2 being >1 cm, or >30 total hyperplastic polyps) requires intensive surveillance. 3
Need for Full Colonoscopy After Sigmoidoscopy
If adenomatous polyps are found on sigmoidoscopy, colonoscopy is generally indicated to exclude synchronous proximal neoplasia, particularly for polyps ≥1 cm, multiple adenomas (>3), advanced histology, or in patients ≥65 years. 2
The risk of advanced proximal neoplasia with 1-2 small distal adenomas is <10%, making colonoscopy optional based on patient preferences, age, and comorbidity. 2
Quality Assurance Requirements
A high-quality baseline colonoscopy is essential: complete examination to cecum, adequate bowel preparation, minimum withdrawal time of 6 minutes, and complete removal of all detected neoplastic lesions. 1
If the first surveillance colonoscopy shows only 1-2 small tubular adenomas or is normal, extend the subsequent interval to 5 years. 1
If high-risk adenomas are detected at first surveillance, maintain the 3-year interval. 1